Staple driving mechanism



2 Sheets-Sheet 1 Filed Feb. 5, 1958 /NVE/V7'OE WAIT" H. HOLLEY W 3.16ATTORNEX Feb. 10, 1959 w. H. HOLLEY STAPLE DRIVING MECHANISM 2Sheets-Sheet 2 Filed Feb. 5, 1958 .mm b i Q 5 m 27% if M T f: swfivvws Ew Q m h m 4 w m 4 United States STAPLE DRIVING MECHANISM ApplicationFebruary 5, 1958, Serial No. 713,500

Claims priority, application Great Britain February 18, 1957 1 Claim.(Cl. 1-49) The present invention relates to a staple-driving mechanism.In most staple-driving mechanisms the staple travels only a shortdistance down a guideway from the staple magazine before coming intocontact with the work to which the staple is to be applied.

In some constructions of stapling mechanisms, however, it is necessarythat the magazine should be remote from the point at which the staplesare applied to the work, because the staple magazine projects laterallyfrom the staple driver and guideway. A particular example of aconstruction of this kind is a staple rammer which may be usecbforexample, in the manufacture of bedding, for the stapling of coil springsto a bed base in furniture manufacture. In such an application it isnecessary to be able to insert'the stapling head through the springs,and to allow this to be done the laterally projecting magazine has to beat a height sufficient to clear the top of the springs when the staplehead is in contact with the work.

It will be appreciated that in such a construction the staple driverblade has a vlong travel, since it must be capable of being raisedsuificiently in its guideway to pick otl the leading staple from thepack of staples in the magazine.

With this type of staple driving mechanism it is very easy to get twostaples in the staple guideway at the same time by raising the driverblade past the magazine without the preceding staple having beenexpelled from the guideway. As a consequence, the mechanism isfrequently jammed unless special steps are taken to prevent this.

it is the principal object of the present invention to provide astaple-driving mechanism with a means for preventing a further staplebeing picked from the staple magazine until the preceding staple hasbeen expelled from the guideway.

In accordance with the present invention a staple-driving mechanism isprovided with a catch mechanism located within the body of the staplinghead of the mechanism to prevent the staple driver blade being raised toa height sufficient to permit the entry of a staple from the magazineinto the staple guideway, unless the blade has been moved down theguideway substantially to its bottom end. This is achieved by roviding acatch member carried by the staple driver and a sliding sleeve movablethrough a limited distance lengthwise of the staple driver and over thecatch member, the sleeve rendering the catch member inoperative at theupper position of the sleeve and releasing the catch member at its lowerposition, the sleeve being movable between two stops in the body locatedso as to cause thesleeve to move up the stapled driver as the driverreaches the bottom end of its travel and to move down the staple driveras it reaches the top end of its travel. There is also provided acatchengaging stop adapted to engage the catch member during upwardmovement of the driver with the sleeve in its lower position so as toarrest the driver before the blade atent uncovers the magazine. Thecatch-engaging stop may be and preferably is co-incident with the upperstop for the sleeve.

One construction of staple-drivingrammer made in accordance with thepresent invention is hereinafter described with reference to theaccompanying drawings, wherein:

Figure l is a side view of a staple-driving rammer of a type for which acatch mechanism of the present invention is suitable.

Figure 2 is a longitudinal section of the rammer of Figure 1.

Figure 3 is a diagrammatic cut-away perspective of the catch mechanismon a larger scale.

Figures 4 to 7 are sectional side views of the staple driving rammer ofFig. 1 which illustrate the operation of the catch mechanism.

The staple rammer shown in Figures 1 and 2 of the drawings is generallyof well-known construction and only the novel catch mechanism associatedwith it will be described in detail. The stapling head-of the rammerhas, in a conventional manner, a barrel 1 made up of a channel memberhaving a block member between the arms of the channel member at itslower end, so as to define a narrow guideway of just sufficient size topermit the passage of a staple and of the stapledriving blade 2.

A staple magazine 3 of conventional construction projeets laterally fromthe side of the barrel to feed staples individually from ya pack ofstaples into the guideway in a conventional manner.

The staple barrel 1 of the stapling head of the rammer is provided witha rubber grip 4. The staple-driving blade 2 is driven by a staple driverhaving a weighted handleS and a shank 6 guided in the barrel 1, theblade 2 being held in driving connection with the shank 6. In ordinaryoperation the handle 5 is pulled out until the bottom end of the blade 2has cleared the staple magazine and reaches the position shown in Figure4, to permit another staple to be fed into the guideway from themagazine. The blade 2 is then drivable to the position shown in Figure 7in which the bottom end of the blade just reaches the bottom end of thebarrel 1 and further travel of the handle is prevented by contactbetween the handle and the top end of the barrel.

The construction and operation of the rammer up to this point isconventional.

The top end of the driver rod 6 is a round portion 7 and guided in around hole in an end cover member 8 secured to the top end of the barrel1.

The top end of the barrel 1 has a square section guideway for a portion9 of the staple driver, upon which staple driver the staple driver blade2 is carried. The portion ii is of generally square section for movementin this portion of the barrel, but one corner of the square portion ofthe driver is cut away to permit it to pass a bottom end stop 10 in theform of a triangular piece of metal let into one corner of the guideway.The stop 10 and the portion 9 of the driver could, of course, take otherco-operating shapes.

The catch mechanism, which forms the special feature of the presentinvention, is mounted on the round portion 7 of the driver 6. The catchmechanism consists of a bow-shaped catch member 11 having a rounded rearsurface 12 to permit the member 11 to rock on a flat surface 14 on theportion 7, and a square section sleeve 15 adapted to slide in the squaresection portion of the barrel 1.

The operative part of the catch member is the end face 16 and the upperend of the catch member is therefore spring-loaded by means of a smallcompression spring 17 bearing against a ball 18, positioned in a crossdrilling in the portion 7. (The spring 17 and ball 18 are shown explodedin Figure 3 for clarity.)

When the sleeve 15 is at its bottom position, the bottom end of thecatch member 11 is trapped within the sleeve and the upper end of thecatch projects above the surface of the rod, so that the end face 16 israised to its operative position.

If the driver 6 is thrust all the way down, as required for driving astaple, the sleeve 15 hits the bottom end stop 10 and slides up theround portion 7. In so doing, the bow-shaped catch member 11 is rockedon its rounded back surface and moved into an inoperative position inwhich the end face 16 is within the periphery of the portion 7 and doesnot project above its surface.

The top end cover 8 houses a hardened collar 19 which likewise has around aperture through it in which the round portion of the shank isguided. The collar 19 acts as the upper stop for the square sectionsleeve 15, which slides down the round portion 7 when arrested by thisupper stop, until the sleeve comes down firmly against the shoulderprovided by the top of the portion 9 of the driver. The collar 19 thusalso prevents the driver from being drawn up out of the barrel.

When the sleeve 15 is in its upper position, the end face 16 of thecatch member 11, as it lies within the periphery of the portion 7, isable to enter the hole in the collar 19, as shown in Figure 4.

On the other hand, when the end face 16 of the catch member 11 is in itsoperative position, it hits the end surface of the collar 19 and thestaple driver 6 is arrested against further upward movement beforethe'blade 2 has been raised sufliciently to uncover the end of thestaple magazine 3 for the feed of the next staple.

In order to expose a larger surface on the end of the collar 19 for thecatch member 11 to engage, a shallow inclined slot 20 (Figure 7) ispreferably cut in the top end of the barrel wall, into which the upperend of the catch member 11 enters, so that it is pressed outwardly byits spring 17 to project out of the rod farther than it otherwise would.

In this case the catch-engaging stop and the upper sleeve stop areco-incident (both being the collar 19), but it will be appreciated thatby minor modification, other similar and operative arrangements arepossible It will be appreciated that as the staple driver reaches thetop of its travel (Figure 4), the sleeve 15 is pushed down the roundportion 7 of the staple driver to release the catch member 11, the topend of which is then free to move outwardly under the force of thespring 17 when it is withdrawn from the hole in the collar 19. If thedriver is, for instance, only moved as far as the position shown inFigure 5 and then again withdrawn, the upward movement of the driverwill be arrested as shown in Figure 6, and it will be impossible toraise the blade 2 sufficiently to pick another staple from the magazine3 until the catch member is again rendered inoperative by driving theblade 2 to the position shown in Figure 7.

I claim:

In a staple-driving mechanism of the type in which staples are fedconsecutively from a magazine into a staple guideway in the body of themechanism when the bladeof a staple driver is raised sutficiently toclear the magazine, a catch mechanism for preventing the introduction ofa further staple into the staple guideway, the said catch mechanismcomprising a catch member carried by the staple driver and a slidingsleeve movable through a limited distance lengthwise of the stapledriver and over the catch member, the sleeve rendering the catch memberinoperative at the upper position of the sleeve and releasing the catchmember at its lower position, upper and lower stops being positioned inthe body to co-operate with said sleeve, the lower stop being positionedto engage the sleeve and move it lengthwise up the driver and over thecatch as the driver reaches the bottom of its travel and the upper stopbeing positioned to engage the sleeve and move it lengthwise down thedriver to uncover the operative upper end of the catch member as thedriver reaches the top of its travel and to engage the catch member onupward movement of the driver with the sleeve in its lower position soas to arrest the driver before the blade uncovers the magazine.

No references cited.,

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